scholarly journals Substrate Specificity of the Sialic Acid Biosynthetic Pathway†

Biochemistry ◽  
2001 ◽  
Vol 40 (43) ◽  
pp. 12864-12874 ◽  
Author(s):  
Christina L. Jacobs ◽  
Scarlett Goon ◽  
Kevin J. Yarema ◽  
Stephan Hinderlich ◽  
Howard C. Hang ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Substrate Specificity ◽  
Biosynthetic Pathway

Probe sialidase substrate specificity using chemoenzymatically synthesized sialosides containing C9-modified sialic acid

2012 ◽  
Vol 48 (27) ◽  
pp. 3357 ◽  
Author(s):  
Zahra Khedri ◽  
Musleh M. Muthana ◽  
Yanhong Li ◽  
Saddam M. Muthana ◽  
Hai Yu ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Substrate Specificity

scholarly journals Biosynthesis of Caffeine Underlying the Diversity of Motif B’ Methyltransferase

2015 ◽  
Vol 10 (5) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Fumiyo Nakayama ◽  
Kouichi Mizuno ◽  
Misako Kato
Keyword(s):  
Substrate Specificity ◽  
Biosynthetic Pathway ◽  
Catalytic Properties ◽  
Biosynthetic Pathways ◽  
Methyl Transferase ◽  
Purine Alkaloids ◽  
Purine Alkaloid

Caffeine (1,3,7-trimethylxanthine) and theobromine (3,7-dimethylxanthine) are well-known purine alkaloids in Camellia, Coffea, Cola, Paullinia, Ilex, and Theobroma spp. The caffeine biosynthetic pathway depends on the substrate specificity of N-methyltransferases, which are members of the motif B’ methyl-transferase family. The caffeine biosynthetic pathways in purine alkaloid-containing plants might have evolved in parallel with one another, consistent with different catalytic properties of the enzymes involved in these pathways.

Structure and function of an ancestral-type β-decarboxylating dehydrogenase from Thermococcus kodakarensis

2016 ◽  
Vol 474 (1) ◽  
pp. 105-122 ◽  
Author(s):  
Tetsu Shimizu ◽  
Lulu Yin ◽  
Ayako Yoshida ◽  
Yuusuke Yokooji ◽  
Shin-ichi Hachisuka ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Biosynthetic Pathway ◽  
Biochemical Characterization ◽  
Tricarboxylic Acid Cycle ◽  
Thermus Thermophilus ◽  
Catalytic Efficiency ◽  
Lysine Biosynthesis ◽  
Hydrophobic Region ◽  
Thermococcus Kodakarensis ◽  
Ancestral Type

β-Decarboxylating dehydrogenases, which are involved in central metabolism, are considered to have diverged from a common ancestor with broad substrate specificity. In a molecular phylogenetic analysis of 183 β-decarboxylating dehydrogenase homologs from 84 species, TK0280 from Thermococcus kodakarensis was selected as a candidate for an ancestral-type β-decarboxylating dehydrogenase. The biochemical characterization of recombinant TK0280 revealed that the enzyme exhibited dehydrogenase activities toward homoisocitrate, isocitrate, and 3-isopropylmalate, which correspond to key reactions involved in the lysine biosynthetic pathway, tricarboxylic acid cycle, and leucine biosynthetic pathway, respectively. In T. kodakarensis, the growth characteristics of the KUW1 host strain and a TK0280 deletion strain suggested that TK0280 is involved in lysine biosynthesis in this archaeon. On the other hand, gene complementation analyses using Thermus thermophilus as a host revealed that TK0280 functions as both an isocitrate dehydrogenase and homoisocitrate dehydrogenase in this organism, but not as a 3-isopropylmalate dehydrogenase, most probably reflecting its low catalytic efficiency toward 3-isopropylmalate. A crystallographic study on TK0280 binding each substrate indicated that Thr71 and Ser80 played important roles in the recognition of homoisocitrate and isocitrate while the hydrophobic region consisting of Ile82 and Leu83 was responsible for the recognition of 3-isopropylmalate. These analyses also suggested the importance of a water-mediated hydrogen bond network for the stabilization of the β3–α4 loop, including the Thr71 residue, with respect to the promiscuity of the substrate specificity of TK0280.

scholarly journals Facile Anomer-oriented Syntheses of 4-Methylumbelliferyl Sialic Acid Glycosides

2021 ◽  
Author(s):  
Abdullah Hassan ◽  
Stefan Oscarson
Keyword(s):  
Catalytic Activity ◽  
Sialic Acid ◽  
Substrate Specificity ◽  
Enzymatic Activity ◽  
Addition Reaction ◽  
Neuraminic Acid ◽  
Acetylneuraminic Acid ◽  
Diastereoselective Addition ◽  
High Yields ◽  
Stereoselective Syntheses

<p>As part of a program to find new sialidases and determine their enzymatic specificity and catalytic activity, a library of 4-methylumbelliferyl sialic acid glycosides derivatised at the C-5 position were prepared from <i>N</i>-acetylneuraminic acid. Both α- and β-4-methylumbelliferyl sialic acid glycosides were prepared in high yields and excellent stereoselectivity. Alpha anomers were accessed via reagent control by utilising additive CH<sub>3</sub>CN and TBAI, whereas the beta anomers were synthesised through a diastereoselective addition reaction of iodine and the aglycone to the corresponding glycal followed by reduction of the resulting 3-iodo compounds. Both anomer-oriented synthetic pathways allow for gram-scale stereoselective syntheses of the desired C-5 modified neuraminic acid derivatives for use as tools to quantify the enzymatic activity and substrate specificity of known<b> </b>sialidases, and potential detection and investigation of<b> </b>novel sialidases.</p>

scholarly journals Synthesis of hydroxycinnamoyl shikimates and their role in monolignol biosynthesis

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dharshana Padmakshan ◽  
Vitaliy I. Timokhin ◽  
Fachuang Lu ◽  
Paul F. Schatz ◽  
Ruben Vanholme ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Caffeic Acid ◽  
Biosynthetic Pathway ◽  
Shikimic Acid ◽  
Sinapic Acid ◽  
Enzyme Characterization ◽  
Hydroxycinnamic Acids ◽  
Coumaric Acid ◽  
Monolignol Biosynthesis

Abstract Hydroxycinnamoyl shikimates were reported in 2005 to be intermediates in monolignol biosynthesis. 3-Hydroxylation of p-coumarate, originally thought to occur via coumarate 3-hydroxylase (C3H) from p-coumaric acid or its CoA thioester, was revealed to be via the action of coumaroyl shikimate 3′-hydroxylase (C3′H) utilizing p-coumaroyl shikimate as the substrate, itself derived from p-coumaroyl-CoA via hydroxycinnamoyl-CoA: shikimate hydroxycinnamoyltransferase (HCT). The same HCT was conjectured to convert the product, caffeoyl shikimate, to caffeoyl-CoA to continue on the pathway starting with its 3-O-methylation. At least in some plants, however, a more recently discovered caffeoyl shikimate esterase (CSE) enzyme hydrolyzes caffeoyl shikimate to caffeic acid from which it must again produce its CoA thioester to continue on the monolignol biosynthetic pathway. HCT and CSE are therefore monolignol biosynthetic pathway enzymes that have provided new opportunities to misregulate lignification. To facilitate studies into the action and substrate specificity of C3H/C3′H, HCT, and CSE enzymes, as well as for metabolite authentication and for enzyme characterization, including kinetics, a source of authentic substrates and products was required. A synthetic scheme starting from commercially available shikimic acid and the four key hydroxycinnamic acids (p-coumaric, caffeic, ferulic, and sinapic acid) has been developed to provide this set of hydroxycinnamoyl shikimates for researchers.

scholarly journals Substrate Specificity of Equine and Human Influenza A Virus Sialidase to Molecular Species of Sialic Acid

2016 ◽  
Vol 39 (10) ◽  
pp. 1728-1733 ◽  
Author(s):  
Tadanobu Takahashi ◽  
Saori Unuma ◽  
Sawako Kawagishi ◽  
Yuuki Kurebayashi ◽  
Maiko Takano ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Substrate Specificity ◽  
Influenza A Virus ◽  
Molecular Species ◽  
Influenza A ◽  
Human Influenza

The relation of three-dimensional structure to biosynthesis in the N-linked oligosaccharides

1983 ◽  
Vol 61 (9) ◽  
pp. 1067-1078 ◽  
Author(s):  
Jean-Robert Brisson ◽  
Jeremy P. Carver
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Potential Energy ◽  
Substrate Specificity ◽  
Biosynthetic Pathway ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Potential Energy Calculations ◽  
Single Orientation ◽  
Structural Classes

The three-dimensional structures are presented for representative N-linked oligosaccharides drawn from four major structural classes. The nuclear magnetic resonance evidence leading to these structures is summarized and the conclusions are compared with those obtained from potential energy calculations and from the crystal structures of fragments. The major finding is that the Manα1-3 arm structure is invariant throughout the series, whereas the Manα1-6 arm has two possible orientations in some structures and a single orientation in others. Finally, the three-dimensional structures permit a rationalization of the substrate specificity of several key enzymes in the biosynthetic pathway.

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